This invention relates to a method for separating blood into a solid part including blood corpuscles and a liquid part including serum by centrifugation, and a barrier used for such method.
In a blood test, blood is generally separated into serum and cellular solid matters such as blood corpuscles by centrifugation, and only the serum is collected for analysis and examination. According to a well-known method for separating the serum, blood collected in a test tube is centrifuged, material such as gel material composed of silicone-silica which has an intermediate specific gravity between those of the serum and cellular solid matters is put in the test tube, the gel material is interposed between the serum and cellular matters by centrifugation, and the serum is separated by decantation. In this case, however, it is difficult perfectly to prevent fibrin and other solid matters from being mixed in the serum.
Such mixing of blood corpuscles, fibrin, etc. in the serum is undesirable because it may cause clog of instrument nozzle as well as errors in measurement.
Accordingly, as a blood separator capable of preventing such mixing in the serum, there is proposed a piston member in which a solid weight for specific gravity adjustment is coupled with a flexible fiber member which is large enough to be in slidable contact with the inside wall of a blood-collecting tube, and having a specific gravity of 1.03 to 1.09 as a whole is inserted in the blood-collecting tube (United States Pat. No. 3,931,018). Formed of two submembers with different specific gravities, porous and solid submembers that are bonded together, the piston member is not an entirely satisfactory structure, requiring much labor in manufacture.
This invention is contrived in consideration of the above circumstances, and is intended to provide a method for separating blood and a device therefor capable of simplifying manufacture and reducing production cost without any possibility of causing blood cells, fibrin, and other solid matters to be mixed with serum.